| 摘要 |
PURPOSE:To absorb vibrations and prevent noises, by a construction wherein a cylindrical solid elastic member is fixed to the periphery of a shaft having a predetermined length. CONSTITUTION:A central hole 8 of a cylindrical solid rubber 7 having a predetermined wall thickness is fitted over the periphery of the shaft 6, leaving predetermined lengths at both end parts of the shaft 6. The outer peripheral surface of the rubber 7 is polished. To prevent the rubber 7 from being bent at the time of polishing, the diameter of the shaft 6 is preferably set to be not less than 10mm. when the length l of the rubber 7 is 340mm.. To prevent the rubber 7 from being deformed by variations in the atmospheric temperature, a rubber material having a low coefficient of thermal expansion is selected. In a platen 5 thus constituted, an impact force at the time of typing is transmitted from the rubber 7 to the shaft 6. Accordingly, the impact sound generated at the time of typing is prevented from being echoed in the interior of the platen 5. |
